There are some tips for this encounter I can offer, whilst they never worked with me (I'm not really geared for the encounter yet), I hope they can be of use for you.

Firstly, ensure you have all members of you raid fully flasked with food buffs. This is something that goes without saying, I'm sure.

You need to note that hogger uses three key abilities in the encounter, of which he uses differently from phase to phase. Since no one to my knowledge has ever reached the third (and final) phase, my knowledge is limited at that point. You need to watch out in phase one for the Head Butt ability. It will stun an enemy, rendering it unable to move or attack for 2 seconds. This ability can be used on the main tank, and Hogger will show no mercy in how he uses this. In phase one he only uses this ability, so it's not too bad if you keep the DPS up and the main tank alive.

Phase 2, Hogger continues the headbut spam, and begins casting Rushing Charge, which increases his movement speed by 60% for 3 seconds and causes him to inflict additional damage on his next attack. This can be a real killer if your healers are not prepared, as when coupled with the Head Butt (they can be used in conjunction) it can be devestating. Keep the HoTs up and be sure to Bandage where needed, this is a long and arduous fight and healers will need all the mana they can get to keep up your tank.

Phase 3.. who knows, if you know then do tell!